Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
  • C07F7/02—Silicon compounds
  • C07F7/08—Compounds having one or more C—Si linkages
  • C07F7/18—Compounds having one or more C—Si linkages as well as one or more C—O—Si linkages
  • C07F7/1896—Compounds having one or more Si-O-acyl linkages

Definitions

• the object was now to provide a process for the production of organosilyl carbonates, in particular bistriorganosilyl carbonates, which is relatively easy to carry out on a relatively large scale, from relatively easily accessible starting materials. This object is achieved by the invention.
• the invention relates to a process for the preparation of organosilyl carbonates, characterized in that organohalosilane is reacted with alkali hydrogen carbonate and amine or phosphine or amine and phosphine in an aprotic solvent which is inert to the reactants, and the mixture of ammonium or. Phosphonium halide is freed and the organosilyl carbonate is isolated from the mixture freed from the halide.
• organosilicon compounds formed from triorganohalosilane and sodium hydrogen carbonate are triorganosilanol or hexorganodisiloxane (cf. W. Noll "Chemistry and Technology of Silicones", Weinheim 1968, page 168).
• organohalosilanes used in the process according to the invention are preferably those of the formula R a SiX 4 .a wherein R is the same or different monovalent SiC-bonded organic radicals, X is the same or different halogen atoms and a is 1, 2 or 3, preferably 3.
• X can be fluorine, chlorine, bromine or iodine. However, chlorine is preferred because of its easy accessibility.
• Examples of monovalent SiC-bonded organic radicals R are hydrocarbon radicals with 1 to 18 carbon atoms per radical, such as alkyl radicals, e.g. the methyl, ethyl, n-propyl, n-butyl and sec-butyl radical and octadecyl radicals; Cycloalkyl radicals, such as the cyclohexyl radical; Hydrocarbon residues with 2 to 18 carbon atoms per residue and aliphatic carbon-carbon multiple bonds, e.g. the ethynyl, vinyl, allyl, and methally radical and styryl radicals; Aryl residues, e.g. the phenyl radical; Alkaryl groups such as tolyl groups; and aralkyl residues, e.g. the benzyl radical.
• alkyl radicals e.g. the methyl, ethyl, n-propyl, n-butyl and sec-butyl radical
• hydrocarbon radicals can have substituents which are inert to Si-bonded halogen and alkali metal bicarbonate.
• substituted hydrocarbon radicals are halogenated, monovalent hydrocarbon radicals, such as the 3-chloropropyl, 3,3,3-trifluoropropyl radical, o-p and m-chlorophenyl radical and bromotolyl radicals; monovalent aliphatic radicals composed of carbon, hydrogen, ether oxygen and fluorine atom (s), such as the 1,1,2,2,3,3-hexafluoropropyloxypropyl radical and the 1,1,22, tetrafluoroethoxypropyl radical, and ether oxygen as the only ones Monovalent hydrocarbon radicals containing substituents, such as the p-methoxyphenyl radical.
• Trimethylchlorosilane and vinyldimethylchlorosilane are particularly preferred as organohalosilanes used in the process according to the invention.
• sodium bicarbonate is particularly preferred as akali bicarbonate. But it can also e.g. Potassium hydrogen carbonate or lithium hydrogen carbonate can be used.
• alkali metal bicarbonate is preferably used in amounts of at least 1 mol per gram atom of Si-bonded halogen, in particular in amounts of 3 to 5 mol per gram atom of Si-bonded halogen.
• Any compounds of this type which bind hydrogen halide, in particular hydrogen chloride, with the formation of ammonium halides or phosphonium halides can be used as amines or phosphines.
• amines are preferred over phosphines.
• Preferred amines are those which are liquid at room temperature and have a boiling point of at most 50 ° C. at 150 hPa (abs.), In particular hexamethyldisilazene and triethylamine, are preferred. Further examples of amines which can be used in the process according to the invention are cyciohexylamine, piperidine, pyridine, chloroethyldimethylamine and n-butylamine.
• Trin-butylphosphine may be mentioned as an example of a phosphine which can be used in the process according to the invention.
• Amine and / or phosphine is preferably used in the process according to the invention in total amounts of at least 1 mol per gram atom of Si-bonded halogen, in particular in amounts of 3 to 5 mol per gram atom of Si-bonded halogen.
• Preferred aprotic solvents which are inert to the reactants are those which are polar and have a boiling point of at most 50 ° C. at 150 hPa (abs.).
• These solvents can be, for example, polar halogenated hydrocarbons, such as dichloromethane, or ethers, such as diethyl ether.
• dichloromethane is particularly preferred as a solvent in which the reaction of organohalosilane with alkali hydrogen carbonate and amine and / or phosphine is carried out.
• An aprotic solvent which is inert to the reaction participants is preferably used in amounts of 100 to 1200 percent by weight, based on the weight of the organohalosilane used in each case.
• the reaction of organohalosilane with alkali hydrogen carbonate and amine and / or phosphine is carried out by or during the mixing of the reactants. It is preferably carried out at 10 ° to 50 ° C. and at the pressure of the surrounding atmosphere, that is to say at 1020 hPa (abs.) Or about 1020 hPa (abs.).
• this mixture is preferably mixed with an aprotic and non-polar solvent which is inert towards the reaction products in order to ensure that the ammonium or.
• an aprotic and non-polar solvent which is inert towards the reaction products in order to ensure that the ammonium or.
• phosphonium halide from which is then filtered, decanted or centrifuged.
• non-polar solvent is preferably used in amounts of 100 to 1000 percent by weight, based on the weight of the organohalosilane used to produce the desired organosilyl carbonate.
• liberation of the mixture of ammonium or. Phosphonium halide is preferably carried out at 10 ° to 50 ° C. and at the pressure of the surrounding atmosphere, that is to say at 1020 hPa (abs.) Or about 1020 hPa (abs.).
• the entry of water is preferably excluded as far as possible.
• the organosilyl carbonates produced according to the invention can e.g. for the hydrophobization of pyrogenic silicon dioxide or for the silylation of amino acids (cf. Y. Yamamoto and co-workers in Journal of Organic Chemistry, Vol. 38, No. 14, 1973, pages 2521 to 2525).

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• 1985
  • 1985-03-08 DE DE19853508363 patent/DE3508363A1/de not_active Withdrawn
  • 1985-11-25 US US06/801,185 patent/US4675425A/en not_active Expired - Fee Related
• 1986
  • 1986-03-07 AT AT86103070T patent/ATE43600T1/de not_active IP Right Cessation
  • 1986-03-07 JP JP61048742A patent/JPS61207393A/ja active Granted
  • 1986-03-07 EP EP86103070A patent/EP0198205B1/fr not_active Expired
  • 1986-03-07 DE DE8686103070T patent/DE3663665D1/de not_active Expired

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